Ice or frozen earth anchor



FebQZl, 1967 l. L. KINTISH ETAL 3,304,671

ICE OR FROZEN EARTH ANCHOR Filed Dec. 3, 1964 2 Sheets-Sheet 1 INVENTORS. IRVING L. KINTISH BY THOM M. ROAH W i. 50%, (flip. ATTORNEYS Feb. 21, 1967 Filed Dec. 3, 1964 I. L. KIN'TISH ETAL ICE OR FROZEN EARTH ANCHOR 2 Sheets-Sheet 2 INVENTORJZ IRVING L. KINTISH BY THOMAS M ROA CH W a i ATTORNEYS United States Patent 3,304,671 ICE 0R FROZEN EARTH ANCHOR Irving L. Kintish, Rockaway, and Thomas M. Roach, Denville, N.J., assignors to the United States of America as represented by the Secretary of the Army Filed Dec. 3, 1964, Ser. No. 415,835 5 Claims. (Cl. 52-155) The invention described herein may be manufactured and used by or for the Government for governmental purposes without the payment to us of any royalty thereon.

The present invention relates to an earth anchor and particularly .to an ice or frozen earth anchor having improved means therein for giving the anchor a high holding power.

Heretofore, ice or frozen earth anchors were simply conventional pins or stakes manually driven into the ice or frozen earth surface. The pins or stakes used had a ring, hook, or some other suitable means for attachment of a cable or the like thereto. These conventional anchoring pins or stakes provided a small anchoring surface area in contrast to the soft earth anchoring devices having expandable surfaces, multiple blades, wing-like portions etc. Since the pins and stakes have small surface areas their anchoring or holding power is, therefore, low. Consequently, they proved to be unreliable in that they were susceptible to loosening as a result of any vibrations or stress caused by the equipment or objects being secured thereto. Oftentimes the objects being secured would work a stress on the pins of such a magnitude that the pins would pull out of the surface and the object was left to the mercy of natures elements, the winds mainly. The results where often costly and disastrous. To prevent any disaster, constant surveillance of the pins and stakes was required to insure that they remained fixed in the ice or frozen earth surface.

The conventional earth anchors of the type having high holding power, such as those having expandable surface areas, multiple blades, or wing-like portions, are incapable of being used in ice or frozen earth. Their use is exclusive to soft earth. The earth anchor using a propellant for embedding the anchor in the soft surface of the earth facilitates the embedding without increasing the holding power. The same result is obtained in the use of the propellant type earth anchor in ice or frozen earth. Furthermore, the conventional earth anchors are generally complicated in structure and expensive to manufacture. At best, the adaptation of conventional earth anchors to fulfill the need for an ice or frozen earth anchor having a high holding power would be a costly expedient, and the possibility of effective results doubtful. This is made manifest by the fact that no attempt has ever been made to provide an ice or frozen earth anchor in accord with existing conventional soft earth anchor designs. Rather, the aforementioned problems of unreliable and ineffective anchoring in ice and frozen earth has been painfully tolerated.

It is, therefore, an object of the present invention to provide an ice or frozen ground anchor having a maximum holding power.

It is a further object of this invention to provide an ice or frozen earth anchor having a maximum holding power and is simple, relatively inexpensive to manufacture, has a minimum number of operating parts, is very strong and has a long operating life despite high frequency of rough use.

It is also an object of this invention to provide an ice or frozen earth anchor which has means for igniting a combustible material capable of creating a temperature sufiiciently high enough to melt a portion of the ice or soften the frozen earth surrounding the anchor.

3,304,671 Patented Feb. 21, 1967 It is still another object of this invention to provide an ice or frozen earth anchor which has means of readily inserting the ground engaging means thereof into melted ice or softened frozen earth whereupon the ground engaging means become firmly fixed in the ice or frozen earth upon refreezing.

In accordance with the invention a tubular metal body is provided with an axial passage having its lower portion adapted to receive a container of a combustible material, such as thermite, for example. The thermite container is insulated from the upper portion of the tube member by a circular disc of refractory material of low strength characteristics. Disposed in the central portion of the tube member and above the refractory disc are the ground engaging means secured to a circular metal plate. The ground engaging means may be cables, rods, corner anchors attached to rods, or the like. A spring is interposed between the plate member securing the ground engaging means and another plate member held in a fixed position within the tube and having the spring secured thereto. The spring is compressed and urged against the plate member securing the ground engaging means. A cap or flange having an eye hook or some other suitable means for attachment of a cable or the like thereto is removably secured to the upper portion of the tube member. The thermite container has an igniter means attached to it. An ignition wire attached to the igniter is led along the outside of the tube member to above the cap or flange member. The entire assembly is placed into a hole in the ice or frozen earth made specifically for this emplacement. The thermite is ignited producing products of combustion having a temperature high enough to melt or soften a portion of ice or frozen earth surrounding the anchor. When the thermite is expended the ground holding means are forced out of the tube member under the urging of the spring. The ice or frozen earth reforms around the ground holding means thereby providing the anchoring having a high holding power.

The invention will be further understood from the following description, when considered in connection with the accompanying drawings, and its scope is pointed out in the apended claims.

In the drawings:

FIG. 1 is a cross-sectional view through an ice or frozen earth formation showing in elevation, and partly in cross-section, the inventive ice or frozen earth anchor in its ready condition;

FIG. 2 is a cross-sectional view through an ice or frozen earth formation showing in elevation and partly in cross-section the inventive ice or frozen earth anchor in its anchored condition;

FIG. 3 is a longitudinal sectional view of a bottom cap showing in partial section the lower portion of the inventive anchor attached thereto.

Referring to the drawings, in which like reference characters refer to like parts throughout the various figures, and referring particularly to FIG. 1, 10 is an elongate tubular body or housing formed of steel or other suitable material having a flange 11 securely attached to the upper end portion thereof. The inner wall of the upper end portion of the tube 10 is provided with threads 12 to permit an anvil 14 or the like to be screwed therein as shown in FIG. 2. The anvil 14 as shown in FIG. 2 has an eye 15 or some other suitable means for attachment of a cable 16 or the like thereto which is to be anchored relative to the ice or frozen ground by means of our device. The eye 15 may be screwed into the anvil 14 or permanently fixed thereto by welding or the like. A fiat circular plate 17 is disposed in the tube 10 below the threads 12 and at right angles to the tube axis. The plate 17 is secured in the tube 10 by screws 18 or the like extended through the tube wall and threaded into the plate 17. A compression spring 19 extends downwardly from the plate 17 through the tube and coaxially therewith. The spring 19 has its upper end secured to the lower surface of the plate 17 by screws 20 or the like extending through the upper face of the plate 17. The lower end of the spring 19 is secured to the upper surface of a lower circular plate 21 by screws 22 or the like extending through the lower face of the plate 21. The lower plate 21 is carried by the spring 19 for vertical movement within the tube 10 when the spring 19 becomes unstressed as illustrated by FIG. 2.

A plurality of support members 23 are firmly secured by welding or the like to the lower face of the plate 21. A cable 24 which serves as a ground engaging means is firmly secured to each support member 23. In the embodiment of the invention illustrated herein the ground engaging means are the cables 24, but the invention is not limited thereto. Flexible straight metal rods, end anchors attached to cables, curved tongue shaped members, or the like may be used, as the needs require, in substitution for the cables 24. In FIG. 1 the cables 24 of this embodiment are shown compactly coiled in a standby or ready position. In FIG. 2 the cables 24 are shown fully extended in operation. A soled circular disc 25 made of a refractory material such as porcelain or the like is disposed in the tube 10 below the coiled cables 24 and at right angles to the tube axis. The disc 25 is secured to the tube with a plurality of lead pins 26 extending through the tube wall and part way into the refractory disc through its side.

A combustible hypergolic charge 27 such as thermite, for example is disposed in the tube 10 and below the refractory disc 25. The thermite charge 27 extends to the lower end of the tube 10. A pull or draw type fired igniter 28 is attached to the lower end of the tube 10 by means of screws 29 or the like extending through the igniter housing 30 and threaded into the end of the tube wall. The igniter 28 and the igniter housing 30 hold the thermite charge 27 in the tube 10. Connected with the igniter is the lower end of a wire 31 for actuating the igniter. The wire 31 extends upwardly along the outer wall of the tube 10 through a passageway 32 in the flange 11 to a pull ring 33 or the like for gripping by the operator when pulling the wire 31 to ignite the thermite charge 27. When the thermite charge 27 is ignited it will melt away the lead pins 26 thereby rendering the disc 25 free to move axially in the tube 10. Since the spring 19 urges a downwardly directed force on the disc 25 the melting away of the pins 26 will result in progressive downward movement thereof relative to the burning of the thermite charge. The thermite charge will continue to burn melting the surrounding ice until its total charge is expended. The cables 24 are then forced by the urging of the spring 19 to the position where the spring is unstressed as illustrated in FIG. 2 and then by gravity into the melted area. The cables 24 remain in the melted area and the ice refreezes around them.

Generally a hole is made in the ice or frozen earth surface by means of a shaped charge explosive, drill, or the like and the anchor inserted therein. However, if no hole making equipment is available a pointed metal cap or nose 34 may be fitted to the lower end of the tube 10 as llustrated by FIG. 3. This cap or nose 34 having a cylindrical upper portion 35 and a conical pointed lower portion 36 is provided with a longitudinal recess 37 which is adapted to receive the outside diameter portion of the tube 10. The anvil 14 can then be screwed inside the tube 10 and the eye removed. The anchor may then be driven into the ice or frozen earth surface by striking the surface of the anvil 14 with a hammer or the like.

In using the anchor a hole is made in the ice or frozen earth surface by using a suitable shaped charge explosive, a drill, or the like. The anchor device without the anvil 14 installed is then inserted into the hole. If there is no hole making equipment available the cap 36 may be fitted to the lower end of the anchor body 10, the anvil 14 installed in the tube 10, the eye member 15 removed from the anvil, and the anchor driven into the ice or frozen earth surface by striking the surface of the anvil with a hammer or the like. After the anchor is driven into the surface to the desired depth it can then be removed from the ice or frozen earth surface, the cap removed from the body 10 and the anchor reinserted into the hole.

With the anchor in position in the hole as just described the thermite is ignited by pulling the wire 31 which activates the igniter 28. The cables 24 are protected from the burning thermite by the refractory material disc 25 interposed between the thermite charge 27 and the upper portion of the anchor tube 10. When the temperature of the burning thermite reaches the melting point of lead (327 C.) the pins 26 are melted thereby rendering the disc 25 and cables 24 movable axially downwardly in the tube under the urging of the spring 19. The thermite continues to burn until it is exhausted resulting in melting of the surrounding ice to an extent dependent upon the quantity of thermite used. For example, one-half pound of thermite (aluminum and iron oxide) which burns at approximately 3000 C. produces heat energy sufficient to melt one cubic foot of ice. The cables 23 move downwardly following burning thermite under the urging of the spring 19. The spring 19 urges the cables 24 to the position shown by the plate 21 in FIG. 2 where the spring is in the unstressed condition. Thereupon the cables 24 fall downwardly into the melted ice or softened earth under the force of gravity. The anchoring is established when the ice or earth refreezes around the ground engaging means, the cables 24. The anvil 14 may then be screwed into the upper portion of the tube 10, or if the anchor was driven into the surface by hammering the eye member 15 may be screwed into the threaded hole provided therefor in the anvil 14. The anchor is now ready for securing a cable or the like thereto for anchoring an object relative to the ice or frozen ground.

It will be seen that the ice or frozen earth anchor described herein provides an anchor having a high holding power. It is also rugged as well as simple in construction, easy to use and efiicient.

From the foregoing it will be seen that this invention is one well adapted to attain all of the ends and objects hereinabove set forth together with other advantages which are obvious and which are inherent in the structure.

We claim:

1. An ice or frozen earth anchor comprising an elongate tubular member,

a combustible thermite-type charge disposed in the lower end portion of said tubular member,

ground engaging means disposed in said tubular member above said combustible charge having its upper end fixed to said tubular member,

heat insulating means disposed in said tubular member between said ground engaging means and said combustible charge,

means disposed in said tubular member above said ground engaging means urging a downwardly directed force on said ground engaging means, and

means for igniting said combustible change whereby generated heat energy will effect temporary melting of ice when said anchor is vertically disposed in ice or frozen earth.

2. An ice or frozen earth anchor comprising an elongate tubular member,

a flange member fixed to the upper end of said tubular member,

an upper circular plate fixedly attached to and axially aligned transversely within said tubular member,

a compressed coil spring having its upper end fixed to said upper circular plate and disposed axially within said tubular member,

a lower circular plate fixed to the lower end of said coil spring,

said coil spring urging a downwardly directed force on said lower circular plate,

earth engaging means fixed to the lower surface of said lower circular plate,

a circular heat insulating disc fixedly disposed axially in said tubular member below said earth engaging means.

a combustible thermite-type charge disposed in the lower end portion of said tubular member below said heat insulating disc,

an igniter for said combustible charge fixed to the lower end of said tubular member,

a wire actuator for said igni-ter attached to the igniter and extending along the outer wall of said tubular member through said flange member.

3. An apparatus as in claim 2 wherein said ground en- 6 gaging means comprises a plurality of metal cables fixed to said lower circular plate.

4. An apparatus as in claim 2 wherein the upper end portion of said tubular member is fitted with a remova- 'ble anvil, said anvil having an upwardly extending eye member afiixed to its upper surface whereby facility for the securing of a line to said anchor is afforded.

5. An apparatus as in claim 2 having a cap with a downwardly pointed closed end removably fitted over the lower end of said tubular member.

No references cited.

FRANK L. ABBOTT, Primary Examiner.

R. S. VERMUT, Assistant Examiner. 

1. AN ICE OR FROZEN EARTH ANCHOR COMPRISING AN ELONGATE TUBULAR MEMBER, A COMBUSTIBLE THERMITE-TYPE CHARGE DISPOSED IN THE LOWER END PORTION OF SAID TUBULAR MEMBER GROUND ENGAGING MEANS DISPOSED IN SAID TUBULAR MEMBER ABOVE SAID COMBUSTIBLE CHARGE HAVING ITS UPPER END FIXED TO SAID TUBULAR MEMBER, HEAT INSULATING MEANS DISPOSED IN SAID TUBULAR MEMBER BETWEEN SAID GROUND ENGAGING MEANS AND SAID COMBUSTIBLE CHARGE, MEANS DISPOSED IN SAID TUBULAR MEMBER ABOVE SAID GROUND ENGAGING MEANS URGING A DOWNWARDLY DIRECTED FORCE ON SAID GROUND ENGAGING MEANS, AND MEANS FOR IGNITING SAID COMBUSTIBLE CHANGE WHEREBY GENERATED HEAT ENERGY WILL EFFECT TEMPORARY MELTING OF ICE WHEN SAID ANCHOR IS VERTICALLY DISPOSED IN ICE OR FROZEN EARTH. 